Question

replace 384_62 by a digit so taaht the no is divisible by 9

Answer 1

Divisibility rule of 9 is sum of digits should be divisible by 9  
Given 384_62 
Sum of digits = 23 
If we add 4 to 23 it become 27 which is divisible by 9 
So the answer is 4 and the new number is
384462

Hope it helps.

Answer 2

sum of two digits = 23 if we add 4 with 23 it becomes 27 which is divisible by 9